dist: rename skip install eggs to be private.

setuptools/dist.py

@@ -30,7 +30,7 @@ __import__('pkg_resources.extern.packaging.specifiers')
 __import__('pkg_resources.extern.packaging.version')
 
 
-skip_install_eggs = False
+_skip_install_eggs = False
 
 
 class SetupRequirementsError(BaseException):
@@ -340,10 +340,9 @@ class Distribution(Distribution_parse_config_files, _Distribution):
             self.dependency_links = attrs.pop('dependency_links', [])
             assert_string_list(self, 'dependency_links', self.dependency_links)
         if attrs and 'setup_requires' in attrs:
-            if skip_install_eggs:
+            if _skip_install_eggs:
                 raise SetupRequirementsError(attrs['setup_requires'])
-            else:
-                self.fetch_build_eggs(attrs['setup_requires'])
+            self.fetch_build_eggs(attrs['setup_requires'])
         for ep in pkg_resources.iter_entry_points('distutils.setup_keywords'):
             vars(self).setdefault(ep.name, None)
         _Distribution.__init__(self, attrs)